// @ts-ignore
import {readFileSync, readdirSync} from 'fs';

let idPerfix: string = '';
const svgTitle: RegExp = /<svg([^>+].*?)>/;
const clearHeightWidth: RegExp = /(width|height)="([^>+].*?)"/g;

const hasViewBox: RegExp = /(viewBox="[^>+].*?")/g;

const clearReturn: RegExp = /(\r)|(\n)/g;

function findSvgFile(dir: string): any[] {
    const svgRes = [];
    const dirents = readdirSync(dir, {
        withFileTypes: true,
    });
    for (const dirent of dirents) {
        if (dirent.isDirectory()) {
            svgRes.push(...findSvgFile(dir + dirent.name + '/'));
        } else {
            const svg = readFileSync(dir + dirent.name)
                .toString()
                .replace(clearReturn, '')
                .replace(svgTitle, (_: string, $2: string) => {
                    let width = 0;
                    let height = 0;
                    // @ts-ignore
                    let content = $2.replace(clearHeightWidth, (_, s2, s3) => {
                        if (s2 === 'width') {
                            width = s3;
                        } else if (s2 === 'height') {
                            height = s3;
                        }
                        return '';
                    });
                    if (!hasViewBox.test($2)) {
                        content += `viewBox="0 0 ${width} ${height}"`;
                    }
                    return `<symbol id="${idPerfix}-${dirent.name.replace('.svg', '')}" ${content}>`;
                })
                .replace('</svg>', '</symbol>');
            svgRes.push(svg);
        }
    }
    return svgRes;
}

export const svgBuilder = (path: string, perfix: string = 'icon') => {
    if (path === '') return;
    idPerfix = perfix;
    const res = findSvgFile(path);
    return {
        name: 'svg-transform',
        transformIndexHtml(html: string) {
            //含有app-main属性的页面才是项目入口
            if (html.indexOf('app-main') === -1) {
                return html
            }
            return html.replace(
                '<body>',
                `
          <body>
            <svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" style="position: absolute; width: 0; height: 0">
              ${res.join('')}
            </svg>
        `,
            );
        },
    };
};